Magnetron



Jan. 16, 1940. K FWZ f 2,187,149

MAGNETRON Filed March 25, 1939 INVENTOR. KARL F/z/Tz ATTORNEY.

Patented Jan. 16, 1940v MAGNETRON Karl Fritz, Neubabelsberg, Germany, assignor to Telefunken f Gesellschaft fr Drahtlosey Telegraphie m. b. H., `Berlin, Germany, a corpora.-

tion' of Germany Application March 25, 1939, seriarNo. 264,061 -In Germany March 29, 1938 e oiaims. (ol. 25o-27.5)

My inventionrelates to electron discharge devices of the'so-called magnetron type which utilize a magnetic field to influence the electron discharge and particularly to such devices for v51 use in frequency multiplication.

It has been suggested that in a conventional magnetron tube having an anode provided with a multiplicity of slots that the outer circuits be connected with the anode segments such that in 1l)` regard tothe controlling field the segments operate as a double slot magnetron and as regards the useful field as a magnetron with four slots. Therefore, a frequency multiplication of the controlling oscillations is obtained. This separation of the controlling system from the useful system carried out solely in connection withthe circuit results in a very simple tube structure butinvolves possibilities of disturbance due to the mutual iniluence of the two systems. Furthermore it is known to employ-'for remote control a magnetron tube having two anode systems arranged at various distances from the cathode and to apply the potentials for the remote control to the inner system while the useful potentials are derived from the outer system. But in this case the operating data cannot be chosen independently of one another in the manner necessary to obtain an optimum of operation. Furthermore, the emission of secondary electrons of the inner system greatly disturbs the outer system.

It is therefore an object of my invention to provide an improved electron discharge device of the magnetron type suitable for use as a frequency multiplier and in which the objections noted above are minimized.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims, but the invention itself will bestfbe understood by reference to the'following description taken in connection with the accompanying drawing in which the single figure ofl the drawing is a diagrammatic perspective of an electron discharge device made according to my invention. n

In the arrangement according to the invention the control electrodes and useful electrodes are separated in such a manner that contrary to the older arrangements, a mutual inuence is no longer possible. According to the invention lthe magnetron tube comprises a cylindrical electrode having two or a greater number of slots and forming the control system and a second cylindrical electrode having two or a greater number of slots and forming the useful system situated at one side of the control system as the extension thereof. The electrons supplied-by an electron source arranged preferably outside thecontrol system, receive a; longitudinal acceleration in the direction of the electrode system so that 5v they first traverse the control system after which they enter the useful system. 1 l

' In .the drawing the cathode K is positioned at one end of the two plate or two segment electrode St and emits electrons which pass into the conl0- trol system St. In the control system the electrons are grouped in phase and receive a frequency of revolution about `the axis of the system which corresponds to the control frequency. With this frequency of revolution the electrons 15 pass to the useful system N having a multiplicity of anode segments and exciting this system with a double frequency owing to the doubled number of segments. This electrode system N is spaced axially and coaxial with electrode system 20 i St. The outer circuit corresponds to the ordinary magnetron circuits, i. e. the control circuit C1 is inserted between the segments of the control system while the useful circuit C2 is in- .serted between the adjacent segments of the use- 25 ful system whose opposite segments are connected to one another. The magnetic field is supplied by solenoid M. The operating potentials of the two systems likewise correspond toordinary magnetron circuits whose tubes have two 30 slots and four slots. The operating conditions ,are to be set in such manner that the circular guide frequency of the electrons is equal to the control frequency f. The useful frequency is then 2f.

The invention isnot limited to the example of construction. herein shown, for instance a different subdivision of the two systems may be chosen for example for the remote control in the proportion 1 1 with thel same number of segments'of 4o the control system and useful system. `In this way a decoupling of two circuits can be accomplished. Furthermore there may be arranged at the side of the electrode system opposite the outn er. cathode an absorption electrode A on which 45 theelectrons impinge after traversing the useful system. This absorption electrode may be cooled in any known manner. The outside cathode may be placed inside the control system. Finally itis also possible to employ inside the electrode sys- 50 tem anon-heated cathode serving solely for rendering the ield symmetrical such as alreadysuggested for the known outside `cathode tubes.

lExterior couplings between the` control system and the useful system should be avoided and this 55 can be achieved eventually by utilizing additional circuit means or by the relative displacement of the planes of the slots of the two systems as shown.

While I have indicated the preferred embodiments of my invention of which I am now aware and have also indicated only one specic application for which my invention may be employed, it will be apparent that my invention is by no means limited to the exact forms illustrated or the use indicated, but that many variations may be made in the particular structure used and the purpose for which it is employed without departing from the scope of my invention as set forth in the appended claims.

What I claim as new is:

1. An electron discharge device having a plurality of electrode segments surrounding a space and forming a control system, a group of anode segments axially spaced from said electrode segments and coaxial therewith and forming the output system, the number of anode segments being a multiple of the number of electrode segments, means adjacent the end .of the control system for supplying electrons axially of said electrode and anode segments and means for inducing a magnetic iield parallel to and within said electrode and anode segments.

2`. An electron discharge device having a plurality of electrode segments surrounding a space and forming a control system, a group of anode segments axially spaced from said electrode segments and coaxial therewith and forming the output system, the number of anode segments being a multiple of the electrode segments, means adjacent the end of the control system for supplying electrons axially of said electrode and anode segments and means for inducing a magnetic eld parallel to and within said electrode and anode segments, and an absorption electrode adjacent the end of the anode segments opposite the control system for receiving electrons from the electron supplying means.

3. An electron discharge device having a control system comprising a pair of semi-cylindrical electrode elements surrounding a space, and an output system comprising a plurality of pairs of oppositely disposed anode segments spaced axially from and coaxial with the semi-cylindrical electrode elements, opposite pairs of anode segments being electrically connected together, a cathode adjacent the ends of the semi-cylindrical electrodes opposite the anode segments and an absorption electrode adjacent the ends of the anode segments opposite the semi-cylindrical electrode elements and means for inducing a magnetic eld parallel to and Within the space surrounded by said semi-cylindrical electrodes and said anode segments.

KARL FRITZ. 

